I think that the point of this story is that the characters don't actually struggle to survive. There is no universal suffering that they face and struggle against. The only reference to survival we can infer is through the use of the blood sacrifice that is carried out every year, when they select and then kill one member of their community, to ensure good crops. Note how Old Man Warner refers to this old saying that points out the meaning behind this obscure yet terrifying practice:

Used to be a saying about 'Lottery in June, corn be heavy soon.'

The blood sacrifice that is so chillingly described to us is related to fertility rights where the blood of one human is shed to ensure a good harvest. However, the point of this story is precisely that this is an anachronistic and outdated tradition that should have been rendered obsolete. Jackson clearly wants to make the point that there are so many practices and customs that we carry out in the name of tradition out of blindness when we are actually committing acts that are profoundly inhuman.

If the people in this short story struggle to survive, it is because they struggle against the power and weight of tradition that causes even former friends to willfully conspire in the murder of one of their number.